Method for providing subbing layer of photographic film

ABSTRACT

A method for providing a subbing layer on a photographic film where a biaxially stretched and heat-set polyethylene terephthalate film is to be provided with a hydrophilic surface comprising applying an aqueous solution containing hydrogen peroxide to the treated surface, applying ultra violet radiation while the coated surface is wet and then applying a hydrophilic resin solution or gelatin dispersion containing a solvent or swelling agent for the polyethylene terephthalate to thereby form the subbing layer.

United States Patent [191 Omichi et al.

WEB FEEDING METHOD FOR PROVIDING SUBBING LAYER OF PHOTOGRAPHIC FILM Inventors:

Assignee:

Filed:

Appl. No.:

Takenori Omichi; Teppei lkeda; Shunichi Adachihara, all of Kanagawa, Japan Fuji Photo Film Co., Ltd., Kanagawa, Japan Feb. 16, 1972 Foreign Application Priority Data Feb. 17, 1971 US. Cl. 117/47 A, 117/34, ll7/93.1 CD, ll7/93.3l, ll7/l38.8 F Int. Cl. B44d l/06, 844d 1 I092 Field of Search ll7/47 A, 34, 93.1 CD, ll7/93.3l, 138.8 F

References Cited UNITED STATES PATENTS PORTION Japan 46-7238 Ramaika 1l7/93.l CD

Primary Examiner-William D. Martin Assistant ExaminerWilliam R. Trenor Attorney, Agent, or Firm--Sughrue, Rothwell, Mion, Zinn & Macpeak [5 7] ABSTRACT A method for providing a subbing layer on a photographic film where a biaxially stretched and heat-set polyethylene terephthalate film is to be provided with a hydrophilic surface comprising applying an aqueous solution containing hydrogen peroxide to the treated surface, applying ultra violet radiation while the coated surface is wet and then applying a hydrophilic resin solution or gelatin dispersion containing a solvent or swelling agent for the polyethylene terephthalate to thereby form the subbing layer.

4 Claims, 1 Drawing Figure Q 8 WINDING PORTION PATENTE HUYIQISH I 3,849,166

- wmnms PORTION METHOD FOR PROVIDING SUBBING LAYER OF PHOTOGRAPHIC FILM DETAILED EXPLANATION OF INVENTION The present invention relates to a method for providing a subbing layer on polyethylene terephthalate, and particularly to a method for providing a subbing layer on a polyethylene terephthalate film used for photography which is subjected to biaxial stretching and heat setting.

Polyethylene terephthalate film which is subjected to biaxial stretching and heat setting (hereinafter, it is called PET film) has been widely used as the support of sensitive elements, printing elements and photographic films, because it has an excellent mechanical strength and a good dimensional stability. However, it is difficult to bind firmly a sensitive emulsion layer which contains hydrophilic gelatin to the PET film, because the surface of the PET film is hydrophobic though it has excellent properties as the photographic film support. Hitherto, in order to afford an adhesive property to the sensitive emulsion layer, there is a method which comprises applying a hydrophobic resin which adheres well to the PET film and has a good solubility and applying a hydrophilic resin thereto. However, such method for providing a subbing layer is not suitable in economic viewpoint and in preparation steps, since a polymer having a high price must be used and two layers must be provided.

Attempts for improving the above-mentioned faults have been done in Japanese Patent Publication Nos. 2603/68 (corresponds to U.S. Pat. No. 3,475,193) and 2604/68. According to these patents, it becomes possible to provide the PET photographic film, in which the above-mentioned faults were improved, by applying ultraviolet rays to a surface of the PET film support and applying a hydrophilic resin solution or gelatin dispersion in which a mixed organic solvent containing a solvent or swelling agent of PET is used to the treated surface of the PET.

An attempt for reforming the surface of the PET film by applying ultraviolet rays has been done in U.S. Pat. No. 3,360,448. This method comprises dipping a PET film support in a volatile organic solvent which contains an aqueous solution of hydrogen peroxide, and applying ultraviolet rays while the PET is in a wet state.

According to this method, however, it is necessary to dissolve the aqueous hydrogen peroxide solution in a large amount of the volatile organic solvent. This is not preferable in economical viewpoint and in safety of operation. An attempt for substituting the volatile solvent by water in this method has been done. But the aqueous hydrogen peroxide solution becomes waterdrops when applied to the surface of the PET film support, because the surface ofthe PET film is hydrophobic, and consequently uniform treatment can not be expected.

As a result of many studies, it has been found that the PET photographic film support in which the abovementioned faults are improved can be prepared by the following method. Namely, the PET film support is subjected to treatment for affording a hydrophilic property to the surface thereof, such as corona discharging, flame treatment, ultraviolet ray application, ozone oxidation, high frequency treatment, ultrasonic treatment and acid treatment by any common manner. Then an aqueous hydrogen peroxide solution or one containing a water soluble solvent is applied to the treated surface. Then, the treated surface is subjected to ultraviolet ray application while it is in a wet state. To the treated surface, a solution of a hydrophilic resin or a dispersion of gelatin in the solvent (which are prepared using a mixed organic solvent containing a solvent or swelling agent of PET) is applied, by which a subbing layer is produced on the PET film support. According to the method of the present invention, it becomes possible to apply uniformly the aqueous hydrogen peroxide solution which is difficult to apply uniformly to the surface of the hydrophobic PET, because the surface of the PET comes to have a hydrophilic property by practising the above-mentioned surface treatment. Further, it is not necessary to dissolve the aqueous hydrogen peroxide solution in the volatile organic solvent which is expensive and dangerous. Even if the solvent is used, the amount thereof is small. Furthermore, by practising such treatment, hydrogen peroxide on the base does not become water drops at the application of ultraviolet rays in a wet state or at the next drying step, and the base is dried uniformly. Namely, in the case that the surface of the PET base is not treated so as to have the hydrophilic property, it is difficult to apply the aqueous hydrogen peroxide solution to the surface of the PET base and the adhesive property thereof is not improved. The surface treatment for attaining the abovementioned object such as corona discharging, flame treatment ultraviolet ray application, ozone oxidation, high frequency treatment, ultrasonic treatment and acid treatment is well known. Although the degree of the surface treatment differs by the aqueous hydrogen peroxide solution applied at the next step, any treatment may be used so long as the solution is applied uniformly (without producing water drops).

Though the concentration of hydrogen peroxide is not prescribed, 0.001-30 percent is especially effective. It is possible to improve uniformity of the application by adding a water-miscible solvent such as methanol and dioxane, etc. or a surface active agent etc. The aqueous hydrogen peroxide solution can be applied by the well-known method such a dipping method, roll coating method and air-knife method. The treatment for applying the ultraviolet rays in the next step is affected by the degree of wetness of the PET base. In general, the treated PET base having an improved surface property can be obtained when more than 0.1 percent of water on the average of the whole film remains. However, it is clear by Japanese Patent Publication Nos. 2603/68 (corresponds to U.S. Pat. No. 3,475,193) and 2604/68 that the desired adhesive effect is obtained by enhancing the degree of the treatment of ultraviolet ray application in the PET base which is not wet at all. Though the light source used for the ultraviolet ray application is not subject to restriction, a mercury lamp made of quartz is conveniently used. The degree of the ultraviolet ray application differs with the conditions of previous treatment, kind and intensity of the light source, distance between the light source and the object to be applied and temperature of the object to be applied, but, in any case, it can be changed so as not to cause deterioration of the quality of the PET base by the ultraviolet ray application.

A solvent or a swelling agent for PET is included in the hydrophilic resin solution or gelatin dispersion used in the present invention, but the amount of the solvent or the swelling agent can be changed suitably depending on the conditions of radiation, kind of the solvent or swelling agent of PET and kind of another coexisting organic solvents. Further, two or more of the solvent or swelling agents for PET may be used at the same time. Additives used for reinforcement of the subbing layer, improvement of the adhesive property of the support or the photosensitive emulsion layer, prevention of electrostatic charging or coloring of the support, such a hardening agent, antistatic agent, dyes, and hydrophilic or hydrophobic high molecular compoundsv may be added to the solution for providing the subbing layer in addition to the hydrophilic resin, gelatin, gelatin swelling agent, dispersing agent and organic solvent. lf desired, a hardening agent, for example, ethyleneimine derivatives, epoxy derivatives and hydrophobic high molecular compounds, such as a partially saponified vinyl chloride-vinyl acetate copolymer, and especially cellulose nitrate, may be added to the solution for providing the subbing layer, by which the desired adhesive property is obtained by ultraviolet ray application in a period shorter than in the case of not adding such material.

According to the method of the present invention, it is possible to obtain a photographic film having a good surface property and a good adhesive property by decreasing the-amount of ultraviolet ray radiation. Further, the photographic property of the photosensitive emulsion is not affected by such treatment.

In the following, the typical method is explained in Examples, but these are not intended to be limitative thereof. r

The adhesive property of the photosensitive emulsion layer to the film support is determined and evaluated by the following generally used method.

Adhesion test in dry state: surfaces of the emulsion layers on an untreated film and-a treated dry film are scratched by a razor to prepare mesh-like linear scratches (interval between lines: about 4 mm). Then an adhesive tape is stuck on the emulsion layer and peeled off rapidly, such as polyester adhesive tape produced by Nitto Electric Industrial Co., Ltd. In this method, grade A means the case that an unpeeled part is about 95 percent, grade B means the case of being above 70 percent and grade C means the case of being up to 70 percent.

Adhesion test in wet state: in each step of develop- I ment, fixing and washing, the films are scratched on the BRIEF EXPLANATION OF DRAWING The FlGUREis a sectional view of an apparatus for providing a subbing layer of the photographic 'film.

EXAMPLE 1 In the FIGURE. a PET film support 1 having a 30 cm width and 10041. of thickness was sent out from A (web feeding portion) and was subjected to corona discharging between a corona discharge treating roll 2-1 and a rod electrode 2-2 by a common method using a LEPEL type surface treating apparatus. The PET film support was let pass at a 3.0 m/min speed, 10 kc frequency, 0.8 mm interval of the rod electrode film and 50 Wet electric power. Then the treated base was sent to the part 3 for applying an aqueous hydrogen peroxide solution, at which a 0.015 percent aqueous hydrogen peroxide solution was applied by passing through a coating pan 4. The base was then sent to an ultraviolet ray application room 5 where the film was radiated by two 1 kw cylindric quartz mercury lamps 6. (length of arcuate portion: approximately cm) which were disposed at 20 cm from the film surface. The treated film was dried in a drying room 7.-Then the film was sentto a coating room 8where a solution for providing a subbing layer having the following composition was applied by passing through a coating pan 9. The film was then dried in a drying room 10 and rolled at B (winding portion).

Composition of the solution for providing the subbing layer:

Gelatin I part by weight Water I do. Acetic acid l do. Methanol 40 do. Acetone do. Methylene chloride 20 do. p-Chlorophenol 3 do.

Adhesive strength in the dry state and the wet state of a photographic sensitive film which was prepared by applying a gelatin-silver halide emulsion to the PET film support having the subbing layer and drying was superior. Photographic properties of this photographic sensitive film were excellent.

In this example, when 0.4. part by weight of cellulose nitrate were added to the solution for providing the subbing layer, treatment for providing the subbing layer could be carried out without any trouble and the adhesive property of the resulting film in the dry state was further improved.

On the contrary, when the corona discharging or the application of hydrogen peroxide was omitted or when the solution for providing the subbing solution was not applied even if the corona discharging treatment and the application of hydrogen peroxide solution were carried out, the adhesive property of the resulting photographic sensitive film in the dry state and the wet state was inferior. Results of such determinations are shown in the FIGURE. The determination were carried out by the above-mentioned method, and evaluation are exhibited by the above-mentioned A, B and C.

TABLE 1 Method for Providing Subbing Layer Adhesion in Wet State Adhesion in Dry State 2 Ultraviolct ray application.

Application of solution for C- C providing subbing layer.

3 Corona discharging.

Application of aqueous hydrogen peroxide solution. C C Ultraviolet ray application.

EXAMPLE 2 A PET film support having a 75p. thickness and a 30 cm width was treated by passing at a speed of 4.0 m/min., kc frequency a, 0.8 mm interval between rod electrode-film and 100W of electric power using the same apparatus as in Example 1. Then an aqueous hydrogen peroxide solution prepared by dissolving parts by volume of methanol in 80 parts by volume of a 0.01 percent aqueous hydrogen peroxide solution was applied thereto. After applying ultraviolet rays and drying by the same manner in Example 1, a solution for providing the subbing layer having the following composition was applied. After drying the film was rolled.

Composition of solution for providing subbing layer:

Maleic anhydride-vinyl acetate (lzl) copolymer 1.3 parts by weight Methanol 45 do. Acetone 20 do. Methylene chloride do. Monochloroaeetic acid 10 do. Chrome acetate 0.4 do.

Adhesive strength in the dry state and the wet state of a photographic sensitive film produced by applying gelatin silver halide emulsion to the film support having the subbing layer and drying was superior. Photographic properties of the resulting photographic sensitive film were excellent.

On the contrary, when the corona discharging or the application of hydrogen peroxide solution was omitted or when the solution for providing the subbing layer was not applied even if the corona discharging treatment and the application of the hydrogen peroxide solution were carried out, the adhesive property of the resulting photographic sensitive film in the dry state and the wet state was inferior. Results of these determinations are shown in Table 2. The manner of evaluation is the same as in Table 1.

TABLE 2 Method for Providing Subbing Adhesion in Adhesion in Layer Dry State Wet State l Corona discharging.

Application of aqueous hydrogen peroxide solution. A A

Ultraviolet ray application. Application of solution for providing subbing layer.

Ultraviolet ray application. Application of solution for C C providing subbing layer.

3 Corona discharging.

Application of aqueous C C hydrogen peroxide solution. Ultraviolet ray application.

EXAMPLE 3 l5 liter/hour). Then a 0.005 percent aqueous hydrogen peroxide solution was applied to the treated surface. After applying ultraviolet rays and drying by the same manner as in Example 1 and 2, a solution for providing the subbing layer having the following composition was applied. After drying the film was rolled.

Composition of solution for providing subbing layer:

Gelatin 0.4 parts by weight Water 0.4 do. Salicylic acid 0.2 do. Methanol 20 do. Acetone 55 do. Methylene chloride 14 do. Phenol 5 do. Tetrachloroethane 5 do.

Adhesive strength in the dry state and the wet state of a photographic sensitive film which was prepared by applying a gelatin-silver halide emulsion to the PET film support having such subbing layer and drying was superior. Photographic properties of the resulting photographic sensitive film were also excellent.

On the contrary, when the flame treatment or the application of the aqueous hydrogen peroxide solution was omitted or when the solution for providing the subbing layer was not applied even if the flame treatment and the application of the aqueous hydrogen peroxide solution were carried out, the adhesive property of the resulting photographic film in the dry state and the wet state was inferior.

Results of these determinations are shown in Table 3. The manner of evaluation is the same as in Table 1.

Application of solution for providing subbing layer.

2 Ultraviolet ray application.

Application otsolution for C C providing subbing layer.

3 Flame treatment.

Application of aqueous hydrogen peroxide solution. C C Ultraviolet ray application.

What is claimed is:

l. A method of providing a subbing layer for a photographic film comprising the steps of:

(a) providing a biaxially stretched and heat-set polyethylene terephthalate film support;

(b) treating the surface of said support to impart thereto a hydrophilic property;

(0) applying to said treated surface an aqueous solution of hydrogen peroxide or an aqueous solution of hydrogen peroxide further containing a water miscible solvent;

(d) applying ultraviolet rays to said treated surface while said surface is in a wet state from step (c); and

(e) applying a hydrophilic resin solution or gelatin dispersion in a mixed organic solvent containing a solvent or swelling agent for polyethylene tereface treatment of the support in step (b) is by flame treatment.

4. The method as claimed in claim 1, wherein said aqueous hydrogen peroxide solution is a 0.001 to 30 wt. percent of aqueous hydrogen peroxide solution 

1. A METHOD OF PROVIDING A SUBBING LAYER FOR A PHOTOGRAPHIC FILM COMPRISING THE STEPS OF: (A) PROVIDING A BIAXIALLY STRETCHED AND HEAT-SET POLYETHYLENE TEREPHTHALATE FILM SUPPORT; (B) TREATING THE SURFACE OF SAID SUPPORT TO IMPART THERETO A HYDROPHILIC PROPERTY; (C) APPLYING TO SAID TREATED SURFACE AN AQUEOUS SOLUTION OF HYDROGEN PEROXIDE OR AN AQUEOUS SOLUTION OF HYDROGEN PEROXIDE FURTHER CONTAINING A WATER MISCIBLE SOLVENT; (D) APPLYING ULTRAVIOLET RAYS TO SAID TREATED SURFACE WHILE SAID SURFACE IS IN WET STATE FROM STEP (C9; AND (E) APPLYING A HYDROPHILIC RESIN SOLUTION OR GELATIN DISPERSION IN A MIXED ORGANIC SOLVENT CONTAINING A SOLVENT OR SWELLING AGENT FOR POLYETHYLENE TEREPHTHALATE TO THE TREATED SURFACE TO FORM THEREFROM SAID SUBBING LAYER.
 2. The method as claimed in claim 1, wherein the surface treatment of the support in step (b) is by corona discharging.
 3. The method as claimed in claim 1, wherein the surface treatment of the support in step (b) is by flame treatment.
 4. The method as claimed in claim 1, wherein said aqueous hydrogen peroxide solution is a 0.001 to 30 wt. percent of aqueous hydrogen peroxide solution. 